System and method for monitoring the handling of a vehicle

ABSTRACT

A system for monitoring the handling of a vehicle has a plurality of individual systems for influencing the handling of the vehicle, a management device being provided for managing the influence on the handling by the individual systems. A method for monitoring a handling of a vehicle is also described.

FIELD OF THE INVENTION

The present invention relates to a system for monitoring the handling ofa vehicle, having a plurality of individual systems for influencing thehandling of the vehicle. The present invention also relates to a methodof monitoring the handling of a vehicle using a plurality of individualsystems.

BACKGROUND INFORMATION

Systems and methods for monitoring the handling of a vehicle are used inparticular for stabilizing the handling of motor vehicles. A pluralityof different systems exist, which operate on the basis of differentmeasured variables and by influencing different parameters which actupon the handling of the vehicle. Examples of such systems, also knownas vehicle dynamics controls, include the Electronic Stability Program(ESP), Active Body Control (ABC), chassis control with superimposedstabilizing intervention (EAR), front axle steering with superimposedstabilizing intervention (EAS) or rear axle steering.

Since a plurality of these individual systems may be installed in thesame vehicle, it is possible that effects of the stabilizinginterventions of the individual systems become superimposed, creatingthe typical problem of multiple-variable control. The interventions ofthe different individual systems may be superimposed additively and thusresult in an excessive total intervention; in other words: a pluralityof redundant interventions occur. It is also possible that a subtractivesuperimposition takes place, so that ultimately an excessively weakintervention in the vehicle stability occurs. Additive superimpositionof the intervention results mainly in undesirable impairment of drivingcomfort. In the event of subtractive superimposition of theinterventions, there is insufficient vehicle dynamics control, whichrepresents a driving safety problem in particular.

In order to suppress interference of the control measures taken by theindividual systems, it has been proposed that specific signals beexchanged between the individual systems or the critical function areasin the individual systems be suppressed. In this way the systems may bemade to coexist and their actions not to affect one another negatively.The total benefit of the combined system may thus remain as great as thesum of the benefits of the individual subsystems.

SUMMARY

In accordance with an example embodiment of the present invention, amanagement device is provided for managing the influence on the handlingby the individual systems. By managing the stabilization functions ofthe individual systems in a targeted manner, it is possible that thetotal benefit is greater than the sum of the individual benefits. Thismay take place by the management device influencing the effects of theindividual systems as a function of the situation. Thus, vehiclestability with maximum driving comfort and minimum loss of speed may bemaintained. In this manner, the individual systems may act fullyindependently in principle; this means that, without intervention by themanagement device, the effects of the individual systems are independentof one another. The management device does not intervene until theindividual systems might exert an undesirable influence on one another.In this context, it may be advantageous in particular if in the event ofa failure of the management device, it may be ensured that theindividual systems continue to deploy their vehicle stabilizing actions,which is particularly useful from the point of view of driving safety.The subsystems may also be developed and calibrated separately.

In example systems, ESP, EAS, EAR and/or ABC may be provided asindividual systems. These individual systems are mentioned as examples,without restricting the generality of the present invention, which maycontain any desired individual systems.

In an example embodiment, the management device may be implemented in acontrol unit which communicates with control units of the individualsystems via an interface. Such an interface may be implemented, forexample, within a CAN system. The management device may receiveinformation via CAN or another interface about the activity of theindividual systems. This information may be formulated either directlyas an effective moment about the vertical axis acting upon the vehicle'scenter of gravity or a force acting upon the vehicle's center ofgravity. It may also be represented as an mediator variable, which isconverted in the management device to a moment basis. Conversely, thecontrol units of the individual systems may receive information from themanagement device via the interface, i.e., via CAN, for example, so thatthe actions of the individual systems are influenced.

In an example embodiment, the management device is implemented in aseparate control unit. The management device is, thus, independent ofthe control devices of the individual systems in terms of the hardware.The systems may therefore be developed and calibrated independently ofone another.

The management device may also be implemented in one or more controlunit(s) of the individual systems. The control units of the individualsystems are hardware components, which are available anyway. Thus, thehardware cost may be reduced by implementing the management devicewithin these control units of the individual systems.

In one example embodiment of the present invention, setpoint valuesdetermined by the individual systems and actual values are input intothe management device; the potential effects of the individual systemsare determined from the input values, and the management device mayoutput values which influence the effects of individual systems. Themanagement device, thus, acts preventively on any undesirableinterventions. The setpoint values determined by the individual systemsare detected by the management device and, taking into account theactual values associated with the respective variables, are adjusted toone another. Thus, the management device may output values so that theeffects of the individual systems are adjusted as needed.

In this context, it is considered particularly advantageous that themanagement device may suppress interventions by individual systems. Inthis variant, the individual systems operate completely independently ofone another when no intervention by the management device takes place.This is advantageous, for example, in the event of a failure of themanagement device. The individual systems are in this case still fullyfunctional. Only when interventions by individual systems are to besuppressed does the management device takes action. In this case, forexample, the transmission of an acknowledge signal indicating whetherthe stabilizing intervention proposed by the individual system is to besuppressed may be sufficient. For example, a symbolic digital 1 may beused for suppression, and a symbolic digital 0 or no signal transmissionmay be used for full implementation of the stabilizing intervention.

The present invention builds on the generic method in that a managementdevice is provided for managing the influence on the handling by theindividual systems. In this way, the advantages of the system accordingto the present invention are implemented in the method. In the exampleembodiments of the method described in the following, possibleadvantages and particular features of the respective system embodimentsare also noted.

In example methods according to the present invention, ESP, EAS, EARand/or ABC may be provided as individual systems.

In one example embodiment, the method is refined by the fact that themanagement device is implemented in a control unit which communicateswith control units of the individual systems via an interface.

In another example embodiment, the management device is implemented in aseparate control unit. However, it may of course also be useful toimplement the management device in one or more control unit(s) of theindividual systems.

In one example embodiment of the method according to the presentinvention, setpoint values determined by the individual systems andactual values are input into the management device; the potentialeffects of the individual systems are determined from the input values,and the management device may output values which influence the effectsof individual systems.

In this context, it may be advantageous if the management device maysuppress interventions by the individual systems.

The present invention is based on the principle that the total benefitsof the systems may be greater than the sum of the individual benefitsdue to the targeted management of the individual systems' stabilizationfunctions. This may occur, for example, by suppressing interferinginterventions as a function of the situation, while specific requiredinterventions are jointly allowed. The subsystems may be developed andcalibrated independently from one another; only the possibility ofinformation exchange should be ensured. Any desired configuration levelsmay also be implemented within a vehicle's range of options. Attentionshould be paid to the correct handling of interfaces in all controlunits involved. Thus, the development and calibration of the managementdevice may be essential for the joint operation of all individualsystems in the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram illustrating an example system according tothe present invention.

FIG. 2 shows a block diagram illustrating a vehicle stability managementsystem.

FIG. 3 shows a μ-slip curve for a tire model in the longitudinaldirection of the tire.

FIG. 4 shows a μ-slip curve for a tire model in the transverse directionof the tire.

FIG. 5 shows a diagram for elucidating the angular relationships of thetire forces.

FIG. 6 shows a flow chart for elucidating a tire force computation forforces applied bidirectionally.

FIG. 7 shows a flow chart for elucidating the computation of a tireforce and a change in tire force in an ESP longitudinal forceintervention.

FIG. 8 shows a flow chart for elucidating the computation of a tireforce and a change in tire force in an EAS lateral force intervention.

FIG. 9 shows a diagram for elucidating a vehicle model for computing themoments about the vertical axis acting on the vehicle's center ofgravity.

FIG. 10 shows a flow chart for elucidating the computation of momentsabout the vertical axis acting on the vehicle's center of gravity.

FIG. 11 shows a flow chart for elucidating the computation of a momentacting on the center of gravity by summation.

FIG. 12 shows a flow chart for elucidating the computation of a momentacting on the center of gravity by summation in ESP longitudinal forceintervention.

FIG. 13 shows a flow chart for elucidating the computation of a momentacting on the center of gravity by summation in EAS lateral forceintervention.

FIG. 14 shows a flow chart for elucidating the formation of interventionmoments in ESP and EAS for an intervention evaluation.

FIG. 15 shows a flow chart for elucidating the prioritization,evaluation, and selection of stabilizing interventions.

DETAILED DESCRIPTION

FIG. 1 shows a block diagram illustrating an example system according tothe present invention. The block diagram shows functional units andarrows symbolizing signals between the individual functional units.Individual signals are symbolized by arrows having a single line. Signalvectors are symbolized by arrows having more than one line. Threeindividual systems 12, 14, 16 are shown as examples. An ESP control unit12, an EAS control unit 14, and an EAR control unit 16 each communicatewith a vehicle stability management control unit 10 via CAN 18 accordingto a valid protocol convention. Vehicle stability management controlunit 10 is illustrated here as a separate control unit. Another optionis to add the additional load of the functions of vehicle stabilitymanagement control unit 10 to one of the existing control units 12, 14,16. Control units 12, 14, 16 of the individual units transmitinformation to vehicle stability management control unit 10, i.e.,values having an influence on the intended interventions in the vehicledynamics in particular. Vehicle stability management control unit 10 inturn transmits values to control units 12, 14, 16 of the individualsystems, for example, a “0” for enabling the action of control units 12,14, 16 of the individual systems and a “1” for blocking those actions.These actions may include, for example, influencing a brake system 20, asteering system 22, or a chassis 24 via appropriate actuators 26.

FIG. 2 shows a block diagram illustrating a vehicle stability managementsystem. The block diagram shows functional units and arrows symbolizingsignals between the individual functional units. Individual signals aresymbolized by arrows having a single line. Signal vectors are symbolizedby arrows having more than one line. Various values are transmitted tothe vehicle stability management system via input 28 of a CAN interface.These values include, for example, a stabilizing setpoint wheel slip byESP 40 and a superimposed steering angle on the front axle forstabilizing by EAS 42. Furthermore, information is transmitted bysubsystems 44. This may include in particular the following variables:slip per wheel, vehicle speed, transverse acceleration, driver steeringangle, steering angle on the wheel, accelerator pedal position, driverbraking pressure, slip angle of the front and/or rear axles, wheelcontact forces, and coefficient of friction.

A differential moment about the vertical axis acting on the vehicle'scenter of gravity generated by a stabilizing chassis intervention of EAR46 is transmitted as an additional variable via input 28 of the CANinterface.

Information 40, 42, 44 is transmitted to a unit 32 for computing thelongitudinal and transverse forces acting on the vehicle tires and thechanges in those forces from physical models of the tire characteristic.Information regarding the longitudinal forces acting on the tires andthe changes in those forces due to longitudinal force intervention 48and regarding the transverse forces acting on the tires and the changesin those forces due to lateral force intervention 50 results from thecomputation in unit 32. Information 48 is transmitted to a unit 34 forcomputing moments about the vertical axis acting on the vehicle's centerof gravity and changes in those moments due to an ESP intervention.Information 50 is transmitted to a unit 36 for computing moments aboutthe vertical axis acting on the vehicle's center of gravity and changesin those moments due to an EAS intervention. The output variable of unit34 is a differential moment about the vertical axis acting on thevehicle's center of gravity by a stabilizing braking intervention 52.The output variable of unit 36 is a differential moment about thevertical axis acting on the vehicle's center of gravity by a stabilizingfront axle steering intervention 54. The latter information 52, 54 istransmitted to a unit for prioritizing, evaluating, and selectingstabilizing interventions 38. The output variables of unit 38 areinstructions for suppressing a longitudinal force intervention 56, alateral force intervention 58, and/or a normal force intervention 60,which are output as a function of the results of unit 38 via the outputof CAN interface 30.

The differential moment about the vertical axis acting on the vehicle'scenter of gravity due to a stabilizing chassis intervention by EAR 46 istransmitted directly to unit 38 for prioritizing, evaluating, andselecting stabilizing interventions and are taken into account by unit38.

In summary, in the unit according to FIG. 2, the incoming signals,possibly converted to a moment about the vertical axis acting on thevehicle's center of gravity, are interpreted as a vehicle stabilizingintervention, added up, weighted, and compared. Furthermore, theintervention(s) to be suppressed is (are) selected and fed back. Forexample, in the illustration according to FIG. 2, it is assumed that ESPtransmits the superimposed setpoint slip for each wheel as acharacterizing variable of the vehicle stability intervention.Additional or other variables are possible. For the EAS, it is assumedthat the superimposed steering angle, which acts to stabilize thevehicle, is used as a transmitted variable. Additional or othervariables are possible. For the EAR, it is assumed that the stabilizingmoment about the vertical axis acting on the vehicle's center of gravitywas directly determined in the EAR control unit on the basis of thedesired and/or planned confirmation of the EAR actuator system andtransmitted and is thus directly available to the vehicle stabilitymanagement control unit. Also in this case additional or other variablesare possible.

FIG. 3 shows a μ-slip curve for a tire model in the longitudinaldirection of the tire. Simplified tire characteristic curves in thelongitudinal direction and a possible approximation as a function of thelongitudinal tire slip and the coefficient of friction of the roadsurface are shown, the parameters set and these characteristic curvesbeing used as examples for a plurality of possible implementations ofthe relationship between longitudinal tire force, longitudinal tireslip, and road surface coefficient of friction. Longitudinal wheel forceμ is plotted on the vertical axis; μ is defined asμ=F _(Lwheel) /F _(Nwheel)i.e., longitudinal wheel force divided by the normal wheel force. SlipS1 is plotted on the horizontal axis. The following equations are usedto approximate the longitudinal forces:μ=√{square root over ((a _(x) ² +a _(y) ²)/g)}where g=9.81 m/s²;

a_(x), a_(y): acceleration in the longitudinal and transversedirections, respectively.

Since no signals for the above computation of the coefficient offriction are available in acceleration-free travel in the longitudinaland transverse directions, a coefficient of friction μ=0.0 is specifiedin this case. In order to avoid problems with such zero values, therange of values of the coefficient of friction is limited toμ_(min)=0.1. μ_(max)=1.0 may be used, for example, as the upper limitvalue. A higher limit value is also possible.

The characteristic values for the approximation of the longitudinalforces are calculated as follows, K1′ denoting a force gradient, and thegiven numerical values being preferably settable.S1′(μ)≈0.04+0.08*μK1′(μ)≈1.00+12.0*μS1″≈0.70%.

The actual approximation of the longitudinal forces using S1 as inputinformation is then done for S1<S1′(μ) according to the equation:F _(L) =F _(n) *K1′(μ)*S1.

Otherwise, longitudinal force F_(L) is determined according to thefollowing equation:F _(L) =F _(n) *K1′(μ)*S1′*(S1′+S1″)/(S1+S1″)

The downward slope of the characteristic curve in the case of high slipS1 is taken into account by the second calculation method of F_(L).

With respect to these computations, it should be pointed out that thecoefficient of friction is referred to the center of gravity of thevehicle. In this way, unequal coefficients of friction on the right andleft sides of the vehicle are taken into account by averaging.

FIG. 4 shows a μ-slip curve for a tire model in the transverse directionof the tire. The lateral tire force, defined asμ=F _(swheel) /F _(Nwheel),i.e., lateral wheel force divided by the normal wheel force, is plottedon the vertical axis of the diagram.

Slip angle parameter α is plotted on the right-hand axis of the diagram.

Reference is made to the discussions on FIG. 3 for determining thecoefficient of friction information.

The setting parameters may be determined on the basis of the followingequations, the numerical values being preferably settable in this casetoo:α′(μ)≈0.80 +4.00*μks′(μ)≈0.11+0.17*μα″≈30°

The actual approximation then takes place according to the followingequations; a distinction is to be made between two cases. In the firstcase, α<α′(μ). The lateral force is then computed according to thefollowing equation:F _(S)(μ,α)=ks′(μ)*α*F _(N).

In other cases, the lateral force is computed according to the followingequation:F _(S)(μ,α)=ks′(μ)*α′*F _(N)*(α′+α″)/(α+α″).

In the second case, the drop in the lateral force for high values of αis taken into account.

For low values of α, the following approximation may also be used:F _(S)(μ,α)≈ks′(μ)*F _(n) *δ=ΔF _(S)(μ)*δ.

In view of the unequal coefficients of friction between the right andleft sides of the vehicle, reference is again made to the discussions onFIG. 3.

FIG. 5 shows a diagram explaining the angular relationships of the tireforces. The square root of the sum of squares of longitudinal tireforces F_(L) (S1, μ, F_(N)) and F_(S) (α, μ, F_(N)) of tire 70, thefirst of which is determined by coefficient of friction μ andlongitudinal slip S1 utilizing coefficient of friction μ, and the secondby coefficient of friction μ and tire slip angle α, forms the total tireforce.F _(R)(λ,μ,F _(N))=√{square root over ((F _(S)(α,μ,F _(N))² +F_(L)(S1,μ,F _(N))²))}{square root over ((F _(S)(α,μ,F _(N))² +F_(L)(S1,μ,F _(N))²))}.

Assuming that the tire characteristic curves are in the linear range inthe longitudinal and transverse directions, i.e., that the slip and theslip angle are small, the slip and slip angle in FIG. 5 may be plottedas shown. In this way, force angle δ may be defined from slip S1 andslip angle α_(S1) astan(δ)=F _(S) /F _(L)=α_(S1) /S ₁.

Due to the non-linearities that arise, this equation does not applyexactly for large slip and slip angle values, but is sufficientlyaccurate in many applications for the estimate used here.

A longitudinal vehicle force F_(L) may be estimated in this way from apredefined wheel force F_(R) asF _(L) =F _(R) *S1/λand transverse tire force may be estimated asF _(S) =F _(R)*α_(S1)/λ.

These equations may be solved relatively easily using longitudinal slipequivalent λ plotted in FIG. 5; divisions by zero must be handled in aspecial way.

In principle, it is possible to determine, on the basis of the tireforce models explained with reference to FIGS. 4 and 5, the longitudinalforce and the transverse force acting on a tire. The above-mentionedmodels, however, assume a unidirectional action of the forces.Superimposition in the case of bidirectional action of the forces shouldbe handled in a special way. If one attempts to determine thelongitudinal force and the transverse force separately and then tosuperimpose one on the other, problematic effects may arise inevaluating the forces due to the non-unambiguous correspondence betweenthe tire forces and the slip angle, as well as between the tire forcesand the slip at the maxima of the curves for medium values.

This may be avoided using the largely valid assumption of a symmetricaltire behavior in the longitudinal and transverse directions, forexample, by the following procedure:

-   -   The maximum transmittable tire force is assumed to be μ*F_(N).    -   The square root of the sum of squares of the slip angle and the        longitudinal slip form a longitudinal slip equivalent λ.    -   The variation of the resulting tire force results from a similar        characteristic model as explained in connection with FIGS. 3 and        4.    -   The tire force is split into longitudinal force components and        transverse force components using the angular relationships,        this split being based on the slip and the slip angle.

The tire forces are approximated using the following equations. Thecoefficient of friction information is again formed as explained withreference to FIG. 3.

The following characteristic values are used, the numerical values beingsettable in this case too.

-   -   P_K_(λ)1≈0.80 [%]    -   P_K_(λ)2≈4.00 [%]    -   P_K_(λ)3≈0.11 [−]    -   P_K_(λ)4≈0.17 [−]    -   P_K_(λ)5≈70.0 [%]

Approximation takes place according to the following equations, brokendown into two cases:λ=√{square root over ((α_(S1) ² +S1²))}λ′(μ)=P _(—) K _(λ)1+P _(—) K _(λ)2*μk _(λ)(μ)=P _(—) K _(λ)3+P _(—) K _(λ)4*μλ″=P_K_(λ)5

First case:λ<λ′(μ).

In this case, the lateral force is computed according to the followingequation:F _(S)(μ,λ)=ks′(μ)*λ*Fn.

In the second case, i.e., λ≧λ′(μ), the lateral force is computed asfollows:F _(S)(μ,λ)=k _(λ)′(μ)*λ′*Fn*(λ′+λ″)/(λ+λ″)

In the second case, the lateral force drops at high values oflongitudinal slip equivalent λ.

Conversion to the longitudinal force is then performed according to theequationF _(L)(μ,λ,S1)=F _(S)(μ,λ)*S1/λ.

Conversion to the transverse force is performed according toF _(L)(μ, λ, S1)=F _(S)(μ, λ)*α_(S1)/λ.

For the discussions regarding the unequal coefficients of frictionbetween right and left vehicle sides, reference is made to FIG. 3.

FIG. 6 shows a flow chart explaining a tire force computation for forcesapplied bidirectionally. The meaning of the individual method steps isprovided first.

-   3201: Start-   3202: P_K_(λ)1=0.80 . . . [%] parameter 1 for determining the    position of the maximum    -   P_K_(λ)2=4.00 . . . [%] parameter 2 for determining the position        of the maximum    -   P_K_(λ)3=0.11 . . . [−] parameter 3 for determining the upward        slope from the origin    -   P_K_(λ)4=0.17 . . . [−] parameter 4 for determining the upward        slope from the origin    -   P_K_(λ)5=70.0 . . . [%] parameter 5 for determining the downward        slope for high values    -   P_K_(αS1)=100.0/45.0 . . . [%/°] conversion factor from slip        angle to slip-   3203: α_(S1)=α*P_K_(αS1) . . . conversion of slip angle to    longitudinal slip equivalent    -   λ=S_(QRT){α_(S1) ²+S1 ²} . . . sum of squares of slip and        longitudinal slip    -   λ′=P_K_(λ) ₁ +P_K_(λ) ₂ *μ . . . maximum tire force, as a    -   function of the longitudinal slip equivalent K_(λ)=P_K_(λ) ₃        +P_K_(λ) ₄ *μ . . . tire force gradient with regard to the        origin of the longitudinal slip equivalent    -   λ″=P_K_(λ) ₅ . . . definition of the downward slope of the tire        force from max. with regard to the longitudinal slip equivalent-   3204: λ<λ′ . . . longitudinal slip equivalent less than value at    maximum tire force?-   3205: F_(R)=F_(N)*K_(λ)*λ′*(λ″+λ′)/(λ+λ″) . . . total tire force    from—maximum with regard to the longitudinal slip equivalent-   3206: F_(R)=F_(N)*K_(λ)*λ . . . total tire force up to—maximum with    regard to the longitudinal slip equivalent-   3207: λ==0 . . . longitudinal slip equivalent equal to 0.0?-   3208: F_(S)=0.0 . . . transverse tire force    -   F_(L)=0.0 . . . longitudinal tire force-   3209: F_(S)=F_(R)*α_(S1)/λ . . . transverse tire force    -   F_(L)=F_(R)*S1/λ . . . longitudinal tire force-   3210: End

After the start in step 3201, parameters for determining the tire forcesare set in step 3202. In step 3203, further variables, which may be usedin steps 3204 through 3210, are determined using the parameters fromstep 3202. In step 3204, first it is determined whether the longitudinalslip equivalent is less than the value at maximum tire force. If this isthe case, in step 3206 the total tire force is computed according to therelationship given there. If this is not the case, in step 3205 anotherrelationship given there is used for computing the total tire force. Instep 3207, it is checked whether the longitudinal slip equivalent isequal to zero. If this is the case, the transverse tire force F_(s) andlongitudinal tire force F_(L) are set to zero, avoiding division byzero. If this is not the case, i.e., the longitudinal slip equivalent isnot equal to zero, the transverse tire force and the longitudinal tireforce are computed according to the relationships given there. In step3210, the method according to FIG. 6 is terminated.

FIG. 7 shows a flow chart explaining the computation of a tire force anda change in tire force in the case of an ESP longitudinal forceintervention. In an ESP intervention, the slip angle on the front axleand on the rear axle are known but predefined variables, while the wheelslip may be influenced in order to vary the longitudinal force. The flowchart of FIG. 7 shows the computation of the instantaneous wheel forcesand changes in wheel forces due to the ESP intervention. This algorithmmust be run for each wheel. First the meaning of the individual steps isdefined.

-   3211: Start-   3212: S1=S1wheel . . . longitudinal slip of the wheel in question-   3213: α=αwheel . . . slip angle of the wheel-   3214: Call the tire force model as a function of S1, α-   3215: F_(S)wheel=F_(S) . . . store lateral force    -   F_(L)wheel=F_(L) . . . store longitudinal force-   3216: S1=S1+S1wheelEsp . . . longitudinal slip intervention for    wheel-   3217: Call the tire force model as a function of S1, α-   3218: ΔF_(SESP)wheel=F_(S)wheel−F_(S) . . . store change in lateral    force    -   ΔF_(LESP)wheel=F_(L)wheel−F_(L) . . . store change in        longitudinal force-   3219: End

After the start of computations in step 3211, in step 3212 thelongitudinal slip of a wheel in question is determined. Subsequently instep 3213, the slip angle of the wheel is determined. In step 3214, thetire force model is called as a function of parameters S1 and α whichhave been determined. In step 3215, the lateral force and thelongitudinal force which have been determined are stored as parametersF_(S)wheel and F_(L)wheel, respectively. In step 3216, the longitudinalslip intervention for the wheel is taken into account. In step 3217, thetire force model is called again as a function of the new parameters S1and α. In step 3218 the change in the lateral force and the change inthe longitudinal force are determined by subtraction and stored. In step3219 the computation of the tire force for the wheel in question isterminated.

FIG. 8 shows a flow chart explaining the computation of a tire force anda change in tire force in an EAS lateral force intervention. In EASintervention, the wheel slip on the front axle and on the rear axle areknown but predefined variables, while the slip angle at least on thefront axle may be influenced in order to vary the lateral force. Theflow chart according to FIG. 8 shows the computation of theinstantaneous wheel forces and changes in wheel forces due to the EASintervention. The slip angle interventions by the EAS are storedseparately for each wheel and made equal to zero for the rear wheels.Thus the algorithm explained with reference to FIG. 8 may be run in thesame way for all wheels and thus even for vehicles having an active rearaxle steering and appropriate signal assignments. The algorithmexplained in the following must be run for each wheel. The meaning ofthe method steps shown in FIG. 8 is explained first.

-   3220: Start-   3221: S1=S1wheel . . . longitudinal slip of the wheel in question-   3222: α=αwheel . . . slip angle of the wheel-   3223: Call the tire force model as a function of S1, α-   3224: F_(S)wheel=F_(S) . . . store lateral force    -   F_(L)wheel=F_(L) . . . store longitudinal force-   3225: α=α+αwheelEas . . . longitudinal slip intervention for the    wheel-   3226: Call the tire force model as a function of S1, α-   3227: ΔF_(SEAS)wheel=F_(S)wheel−F_(S) . . . store change in lateral    force    -   ΔF_(LEAS)wheel=F_(L)wheel−F_(L) . . . store change in        longitudinal force-   3228: End

In step 3220 the computation of the tire force and the change in tireforce for the EAS longitudinal force intervention is initiated. In step3221, the longitudinal slip of the wheel in question is stored asvariable S1. In step 3222, the slip angle of the wheel is stored asvariable α. In step 3223, the tire force model is called using thestored parameters S1 and α. In step 3224, the lateral force and thelongitudinal force of the wheel are stored. Subsequently, in step 3225,a longitudinal slip intervention of the wheel is taken into account anda new variable α is stored. In step 3226, the tire force model is calledagain as a function of the new parameters S1 and α. Subsequently, instep 3227, a change in the lateral force is computed by subtraction andstored. A change in the longitudinal force is also computed bysubtraction and then stored. In step 3228 the method shown in FIG. 8 isterminated.

FIG. 9 shows a diagram explaining a vehicle model for computing thetorques about the vertical axis acting on the center of gravity of thevehicle. The symbols shown in FIG. 9 have the following meanings:

-   δ: steering angle; for EAS, front axle only-   α_(H): tire slip angle, rear axle-   α_(v): tire slip angle, front axle-   ω: vehicle yaw rate-   β: vehicle float angle-   vFz: vehicle speed, straight-ahead-   F_(Lxy): longitudinal tire force on axle x (front v/rear h) and side    y (right/left)-   F_(Sxy): transverse tire force on axle x (front v/rear h) and side y    (right/left)

For the sake of simplicity, it is assumed that the vehicle float angleand the tire slip angle are small and thus a splitting of the forcesinto sine and cosine components may be omitted without major loss ofaccuracy. The moments are determined as follows from the longitudinalforce (index L) and transverse force (index S):

M_(L)=−F_(L)*SW/2 for left wheels

M_(L)=F_(L)*SW/2 for right wheels

M_(S)=−F_(S)*1SpV for front axle

M_(S)=F_(S)*1SpH for rear axle

FIG. 10 shows a flow chart explaining the computation of moments aboutthe vertical axis acting on the center of gravity of the vehicle. Usingthe calculated transverse and longitudinal forces acting on the tire andthe effective lever arm, the moment acting on the center of gravity ofthe vehicle due to the particular wheel, as well as the change in thismoment, may be determined from the changes in the forces due to the ESPand EAS interventions. The values thus determined may be added up forall wheels, which is explained with reference to FIG. 10. The meaning ofthe steps illustrated in FIG. 10 is explained first:

-   3501: Start-   3502: wheel==VL OR wheel ==VR . . . wheel is on front axle-   3503: M_(S)=F_(S)*1SpH . . . moment acting on the vehicle center of    gravity due to the lateral force on the rear axle-   3504: M_(S)=−F_(S)*1SpV . . . moment acting on the vehicle center of    gravity due to the lateral force on the front axle-   3505: wheel==VL OR wheel==HL . . . wheel is on left side-   3506: M_(L)=F_(L)*SW/2 . . . moment acting on the vehicle center of    gravity due to right-side longitudinal force-   3507: M_(L)=−F_(L)*SW/2 . . . moment acting on the vehicle center of    gravity due to left-side longitudinal force-   3508: M_(Sp)=M_(L)+M_(S) . . . moment component acting on the    vehicle center of gravity due to this wheel-   3509: End

After the start of the program flow in step 3501, in step 3502 it isdetermined whether the wheel is on the front axle. If this is the case,in step 3504 the moment acting on the vehicle's center of gravity due tothe lateral force on the front axle is computed. If this is not thecase, in step 3503 the moment acting on the vehicle's center of gravitydue to the lateral force on the rear axle is computed.

Subsequently, in step 3505, it is determined whether the wheel is on theleft vehicle side. If this is the case, in step 3507 the moment actingon the vehicle's center of gravity due to a longitudinal force on theleft side is determined. If this is not the case, in step 3506 themoment acting on the vehicle's center of gravity due to a longitudinalforce on the right side is determined.

Subsequently, in step 3508, the moment component acting on the vehicle'scenter of gravity due to the wheel in question is determined by theaddition of the moments determined in steps 3503 or 3504 and 3506 or3507. In step 3509 the program flow is terminated.

FIG. 11 shows a flow chart explaining the computation of a moment actingon the vehicle's center of gravity by summation. The meaning of themethod steps shown in FIG. 11 is explained first.

-   3510: Start-   3511: M_(yaw)=0.0 . . . default value for moment acting on the    vehicle's center of gravity-   3512: F_(L)=F_(L)wheel_(VL)    -   F_(S)=F_(s)wheel_(VL) . . . front left-   3513: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3514: M_(yaw)=M_(yaw)+M_(Sp) . . . yaw moment from adding up moments    acting on the vehicle's center of gravity-   3515: F_(L)=F_(L)wheel_(VR)    -   F_(S)=F_(S)wheel_(VR) . . . front right-   3516: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3517: M_(yaw)=M_(yaw)+M_(Sp) . . . yaw moment from adding up moments    acting on the vehicle's center of gravity-   3518: F_(L)=F_(L)wheel_(HL)    -   F_(S)=F_(S)wheel_(HL) . . . rear left-   3519: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3520: M_(yaw)=M_(yaw)+M_(Sp) . . . yaw moment from adding up moments    acting on the vehicle's center of gravity-   3521: F_(L)=F_(L)wheel_(HR)    -   F_(S)=F_(S)wheel_(HR) . . . rear right-   3522: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3523: M_(yaw)=M_(yaw)+M_(Sp) . . . yaw moment from adding up moments    acting on the vehicle's center of gravity-   3524: End

The summation of all wheels for determining the moment acting on thevehicle's center of gravity starts in step 3510. Subsequently, in step3511, a default value for the moment acting on the center of gravity isdetermined. In step 3512, the longitudinal and lateral forces of thefront left wheel are stored as variables to be processed further.

In step 3513, these are used in determining the moment about thevertical axis acting on the vehicle's center of gravity. In step 3514,the yaw moment is computed by adding up the moments acting on thevehicle's center of gravity.

In steps 3515 through 3517, the method explained with reference to steps3512 through 3514 for the front left wheel is repeated for the frontright wheel. Then, the method is repeated in steps 3518 through 3520 forthe rear left wheels. Following the computation for the rear left wheel,the method is performed in the same way for the rear right wheel insteps 3521 through 3523. In step 3524 the sequence is terminated.

FIG. 12 shows a flow chart explaining the computation of a moment actingon the vehicle's center of gravity by summation in the case of ESPlongitudinal force intervention. First, the meaning of the method stepsshown in FIG. 12 is explained again.

-   3401: Start-   3402: M_(yaw)E_(SP)=0.0 . . . default value for moment acting on the    vehicle's center of gravity-   3403: F_(L)=F_(L)wheel_(VL)−ΔF_(LESP)wheel_(VL)    -   F_(S)=F_(S)wheel_(VL)−ΔF_(SESP)wheel_(VL) . . . front left-   3404: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3405: M_(yaw)E_(SP)=M_(yaw)E_(SP)+M_(SP) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3406: F_(L)=F_(L)wheel_(VR)−ΔF_(LESP)wheel_(VR)    -   F_(S)=F_(S)wheel_(VR)−ΔF_(SESP)wheel_(VR) . . . front right-   3407: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3408: M_(yaw)E_(SP)=M_(yaw)E_(SP)+M_(SP) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3409: F_(L)=F_(L)wheel_(HL)−ΔF_(LESP)wheel_(HL)    -   F_(S)=F_(S)wheel_(HL)−ΔF_(SESP)wheel_(HL) . . . rear left-   3410: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3411: M_(yaw)E_(SP)=M_(yaw)E_(SP)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3412: F_(L)=F_(L)wheel_(HR)−ΔF_(LESP)wheel_(HR)    -   F_(S)=F_(S)wheel_(HR)−ΔF_(SESP)wheel_(HR) . . . rear right-   3413: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3414: M_(yaw)E_(SP)=M_(yaw)E_(SP)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3415: End

The sequence starts in step 3401. In step 3402, the default value ofzero is initially set for the moment acting on the vehicle's center ofgravity. Subsequently, in step 3403, from the longitudinal wheel forceon the front left wheel and the change in longitudinal force, determinedfor this wheel, a value is determined, which is stored as the variablefor the longitudinal force. Furthermore, from the particular variables,the value of variable F_(s) is determined. In step 3404, the momentabout the vertical axis acting on the vehicle's center of gravity isdetermined using the variables determined in step 3403. In step 3405,the yaw moment is computed by adding up the moments acting on thevehicle's center of gravity.

In steps 3406 through 3408, steps 3403 through 3405, which were executedthere for the front left wheel, are executed for the front right wheel.Then, in steps 3409 through 3411, the method is executed for the rearleft wheel. Finally, in steps 3412 through 3414, the method is executedfor the rear right wheel. In step 3415 the sequence of this program flowis terminated.

FIG. 13 shows a flow chart explaining the computation of a moment actingon the vehicle's center of gravity by summation in the case of EASlateral force intervention.

First, the meaning of the method steps shown in FIG. 13 is explained.

-   3601: Start-   3602: M_(yaw)E_(AS)=0.0 . . . default value for the moment acting on    the vehicle's center of gravity-   3603: F_(L)=F_(L)wheel_(VL)−ΔF_(LEAS)wheel_(VL)    -   F_(S)=F_(S)wheel_(VL)−ΔF_(SEAS)wheel_(VL) . . . front left-   3604: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3605: M_(yaw)E_(AS)=M_(yaw)E_(AS)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3606: F_(L)=F_(L)wheel_(VR)−F_(LEAS)wheel_(VR)    -   F_(S)=F_(S)wheel_(VR)−F_(SEAS)wheel_(VR) . . . front right-   3607: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3608: M_(yaw)E_(AS)=M_(yaw)E_(AS)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3609: F_(L)=F_(L)wheel_(HL)−ΔF_(LEAS)wheel_(HL)    -   F_(S)=F_(S)wheel_(HL)−ΔF_(SEAS)wheel_(HL) . . . rear left-   3610: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3611: M_(yaw)E_(AS)=M_(yaw)E_(AS)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3612: F_(L)=F_(L)wheel_(HR)−ΔF_(LEAS)wheel_(HR)    -   F_(S)=F_(S)wheel_(HR)−ΔF_(SEAS)wheel_(HR) . . . rear right-   3613: Call determination of moment about the vertical axis acting on    the vehicle's center of gravity-   3614: M_(yaw)E_(AS)=M_(yaw)E_(AS)+M_(Sp) . . . yaw moment from    adding up moments acting on the vehicle's center of gravity-   3615: End

After the start of the routine in step 3601, in step 3602 a defaultvalue of zero is set for the moment acting on the vehicle's center ofgravity. Then from the longitudinal force and the calculated change inlongitudinal force, the longitudinal force used for determining themoment about the vertical axis acting on the vehicle's center of gravityis determined. In the same way, the lateral force is determined from thecorresponding values. In step 3604, the determination of the momentabout the vertical axis acting on the vehicle's center of gravity usingthe variables determined in step 3603 is called. In step 3605, the yawmoment is determined by adding up the moments acting on the vehicle'scenter of gravity.

In steps 3606 through 3608, the same method as explained in conjunctionwith steps 3603 through 3605 for the front left wheel, is executed forthe front right wheel. Then, in steps 3609 through 3611, the method isexecuted for the rear left wheel. Finally, in steps 3612 through 3614,the method is executed for the rear right wheel. In step 3615 thesequence of this program flow is terminated.

At this point, it should be pointed out that the sequence of processingoperations given above for the individual wheels may be modified.

FIG. 14 shows a flow chart for explaining the formation of interventionmoments in ESP and EAS for an intervention evaluation. The change inmoments due to the ESP and EAS interventions are considered stabilizingmoments changing the longitudinal and transverse forces, respectively.At this point, other systems having the same effect but differentinterfaces may also be introduced. Since the formation of such aninterface may be highly significant from the point of view of systemengineering, this step is explicitly executed as such.

To form the intervention moment in the direction of the normal force,the computation steps explained in connection with FIG. 14 and discussedin connection with FIGS. 10 through 13 may be used as examples of theprocedure for conclusively evaluating the effect of the interventions inthe normal force distribution regarding the overall vehicle stabilitycompared to systems which influence longitudinal and transverse forces.A signal M_(N) which describes the change in the yaw moment about thevehicle's vertical axis acting on the vehicle's center of gravity isexpected as an interface signal, by analogy with M_(S) for the lateralforce intervention and M_(L) for longitudinal force intervention.

The meaning of the method steps provided in FIG. 14 is explained first.

-   3525: Start-   3526: M_(S)=M_(yaw)E_(AS)−M_(yaw) . . . yaw moment from EAS    intervention minus working point-   3527: M_(L)=M_(yaw)E_(SP)−M_(yaw) . . . yaw moment from [EAS [sic;    ESP]] ESP intervention minus working point-   3528: End

After the start of the routine in step 3525, in step 3526 the interfacesignal for the lateral force intervention is computed as the yaw momentfrom the EAS intervention minus the working point regarding the lateralforce. In a comparable manner, in step 3527, the interface signal forthe longitudinal force intervention is computed by subtraction. In step3528, this subprogram is terminated.

FIG. 15 shows a flow chart explaining the prioritization, evaluation,and selection of stabilizing interventions. Initially the selection ofthe maximum moment M_(SP)Max is explained. The possible interventions inthe moment acting on the vehicle's center of gravity—normal forceintervention, lateral force intervention, and longitudinal forceintervention—are checked as follows:

a) moment due to normal force distribution

b) moment due to lateral force intervention

c) a)+b)

d) g)+a)

e) g)+b)

f) a)+b)+g)

g) moment due to longitudinal force intervention

The number of options is 2^(n-1), where n=3=number of interventionoptions. These options are played out in the sequence mentioned on thebasis of a comparison of absolute values and compared with the requiredmoment acting on the vehicle's center of gravity M_(SP)Max previouslydetermined on the basis of a comparison of absolute values. If M_(SP)Maxis achieved, the first intervention in this sequence is selected andallowed. The prioritization of interventions is thus predefined in thesequence of the above listing.

The vehicle is successfully stabilized in each case, if stabilization isrequested and is possible, using these simple queries. It is possible,for example, that ESP cannot be activated, for example, due to a faultin an ABS valve; however, a required stabilizing moment (setpoint slip)is output by ESP. Its effect is then implemented, for example, by EAR bya normal force intervention and by EAS by a lateral force intervention.

It is also possible, for example, that the moment request by ESP isgreater than that by EAR and EAS. Then the first one is selected asM_(SP)Max, but it is not put through, since the summation of moments dueto normal and lateral force variation is sufficient to represent thismoment.

It is also possible that a sum intervention is weaker and thereforepossibly more comfortable than an individual intervention, for example,by bringing the tire forces into the downward sloping ranges of thecharacteristic curves. Therefore, to check combined interventions,longitudinal force intervention, known to be uncomfortable, is evaluatedlast by the brake system.

In this sequence of the computing steps it is assumed that thelongitudinal force intervention means the least comfort and greatestloss of speed, and a chassis intervention to change the normal forcedistribution offers the greatest comfort. It is also assumed that anintervention into the steering system for building up lateral forcesrepresents little loss of comfort for the driver.

The query for absolute values is performed at this point in order tocompare interventions regardless or their plus or minus signs. The queryis sufficient to permit the correct intervention. However, theprerequisite is that the interventions by the subsystems pursue the sameobjective; otherwise the overall effect is perceptibly non-homogeneous.For example, it is conceivable that at a certain instance a subsystemreduces the float angle of the vehicle to improve vehicle stability, forexample, on the basis of float angle estimation algorithms. Anothersubsystem, however, performs yaw rate control against understeeringtendencies almost at the same time. This might result in a combinationof interventions which makes the influence on the vehicle rapidly andperceptibly go from plus to minus or vice-versa. In developing suchcomposite systems, special attention must be paid to the fact that suchinterventions are perceptible and/or disturbing.

As an alternative to this algorithm, it would be conceivable to weightthe effects of all interventions and, after examining all interventions,select the one that implements the required M_(SP)Max, but keeps thesmallest possible distance to it. This would make a predefinition ofpriorities as done here dispensable. Instead, a priority would becomputed in each cycle. However, this advantage is offset by highercomputing costs.

Before explaining in detail the method illustrated in FIG. 15, themeaning of the method steps shown in FIG. 15 is explained.

FIG. 15 a:

-   3801: Start-   3802: M_(SP)Max: =0 . . . default value for required stabilizing    moment    -   M_(a)): =M_(N) . . . moment from normal force intervention has        1^(st) priority for stabilization    -   M_(b)): =M_(S) . . . moment from lateral force intervention has        2^(nd) priority for stabilization    -   M_(c)): =M_(N)+M_(S) . . . moment from normal plus lateral force        intervention has 3 ^(rd) priority    -   M_(d)): =M_(L)+M_(N) . . . moment from longitudinal plus normal        force intervention has 4^(th) priority    -   M_(e)): =M_(L)+M_(S) . . . moment from longitudinal plus lateral        force intervention has 5^(th) priority    -   M_(f)): =M_(L)+M_(S)+M_(N) . . . moment from        longitudinal+lateral+normal force intervention has 6^(th)        priority    -   M_(g)):=M_(L) . . . moment from longitudinal force intervention        has 7^(th) priority for stabilization-   3803: InterventionNout=FALSE . . . intervention on normal force may    take place    -   InterventionSout=FALSE . . . intervention on lateral force may        take place    -   InterventionLout=FALSE . . . intervention on longitudinal force        may take place-   3804: |M_(L)|>|M_(SP)Max| . . . stabilizing moment from longitudinal    force intervention greater than required stabilizing moment-   3805: M_(SP)Max=M_(L) . . . moment from longitudinal force    intervention required stabilizing moment-   3806: |M_(N)|>|M_(SP)Max| . . . stabilizing moment from normal force    intervention greater than required stabilizing moment-   3807: M_(SP)Max=M_(N) moment from normal force intervention equal to    required stabilizing moment-   3808: |M_(S)|>|M_(SP)Max| . . . stabilizing moment from lateral    force intervention greater than required stabilizing moment-   3809: M_(SP)Max=M_(S) . . . moment from lateral force intervention    equal to required stabilizing moment

FIG. 15 b:

-   3810: |M_(S)|<|M_(SP)Max| . . . absolute value of stabilizing moment    from a) less than that of required stabilizing moment-   3811: InterventionLout=TRUE . . . longitudinal force intervention    off    -   InterventionSout=TRUE . . . lateral force intervention off-   3812: |M_(b))|<|M_(SP)Max| . . . absolute value of stabilizing    moment from b) less than that of required stabilizing moment-   3813: InterventionLout=TRUE . . . longitudinal force intervention    off    -   InterventionNout=TRUE . . . normal force intervention off-   3814: |M_(c))|<|M_(SP)Max| . . . absolute value of stabilizing    moment from c) less than that of required stabilizing moment-   3815: InterventionLout=TRUE . . . longitudinal force intervention    off-   3816: |M_(d))|<|M_(SP)Max| . . . absolute value of stabilizing    moment from d) less than that of required stabilizing moment-   3817: InterventionNout=TRUE . . . normal force intervention off    -   InterventionSout=TRUE . . . lateral force intervention off

FIG. 15 c:

-   3818: |M_(e))|<|M_(SP)Max| . . . absolute value of stabilizing    moment from e) less than that of required stabilizing moment-   3819: InterventionSout=TRUE . . . lateral force intervention off-   3820: |M_(f))|<|M_(SP)Max| . . . absolute value of stabilizing    moment from f) less than that of required stabilizing moment-   3821: InterventionNout=TRUE . . . normal force intervention off-   3822: End

The program flow starts in step 3801. Subsequently, in step 3802,moments are computed for further processing as a function of thepriorities of the interventions. In step 3803, the output values whichdetermine whether interventions may take place are established.Initially it is established that normal force intervention, lateralforce intervention, and longitudinal force intervention may take place.

In step 3804 it is determined whether the stabilizing moment from thelongitudinal force intervention is greater than the required stabilizingmoment. If this is the case, the moment from the longitudinal forceintervention is stored in step 3805 as the required stabilizing moment.Then, the procedure continues with step 3806. If the query in step 3804is answered with NO, the procedure still continues with step 3806.

In step 3806 it is determined whether the stabilizing moment from thenormal force intervention is greater than a required stabilizing moment.If this is the case, the moment from the normal force intervention isstored in step 3807 as the required stabilizing moment. Then, theprocedure continues with step 3808. If the query in step 3806 isanswered with NO, the procedure still continues with step 3808.

In step 3808 it is checked whether the stabilizing moment from thelateral force intervention is greater than the required stabilizingmoment. If this is the case, the moment from the lateral forceintervention is stored as the required stabilizing moment. Then, theprocedure continues with step 3810. If the query in step 3808 isanswered with NO, the procedure still continues with step 3810.

In step 3810 it is checked whether the absolute value of stabilizingmoment M_(a)) is less than that of the required stabilizing moment. Ifthis is the case, both a longitudinal force intervention and a lateralforce intervention are turned off in step 3811.

If the query in step 3810 is answered with YES, it is determined in step3812 whether the absolute value of stabilizing moment M_(b)) is lessthan that of a required stabilizing moment. If this is not the case, alongitudinal force intervention and a normal force intervention areturned off.

If the query in step 3812 is answered with YES, it is determined in step3814 whether the absolute value of stabilizing moment M_(c)) is lessthan that of the required stabilizing moment. If this is not the case,the longitudinal force intervention is turned off.

If the query in step 3814 is answered with YES, it is checked insubsequent step 3816 whether the absolute value of stabilizing momentM_(d)) is less than that of the required stabilizing moment. If this isnot the case, normal force intervention and lateral force interventionare turned off.

If, however, the query in step 3816 is answered with YES, it isdetermined in step 3818 whether the absolute value of stabilizing momentM_(e)) is less than that of a required stabilizing moment. If this isnot the case, the lateral force intervention is turned off.

If, however, the query in step 3818 is answered with YES, it isdetermined in step 3820 whether the absolute value of stabilizing momentM_(f)) is less than that of the required stabilizing moment. If this isnot the case, the normal force intervention is turned off.

If the query of step 3820 is answered with YES, the procedure isterminated in step 3822. The procedure is also terminated after theparticular intervention variables have been turned off in steps 3811,3813, 3815, 3817, 3819, and 3821.

The preceding description of the exemplary embodiments according to thepresent invention is only used for illustrative purposes and not tolimit the present invention. Various changes and modifications arepossible within the framework of the present invention.

1. A system for monitoring handling of a vehicle, comprising: aplurality of individual systems for influencing the handling of thevehicle; and a management device configured to manage an influence onthe handling by the individual systems; wherein the individual systemsinclude at least two of an Electronic Stabilizing Program (ESP), frontaxle steering with superimposed stabilizing intervention (EAS), andchassis control with superimposed stabilizing intervention (EAR) andActive Body Control (ABC).
 2. The system as recited in claim 1, whereinthe management device is implemented in a control unit whichcommunicates with control units of the individual systems via aninterface.
 3. The system as recited in claim 1, wherein the managementdevice is implemented in a separate control unit.
 4. The system asrecited in claim 1, wherein the management device is implemented in atleast one control unit of the individual systems.
 5. The system asrecited in claim 1, wherein the management device is configured toreceive setpoint values determined by the individual systems and actualvalues as input, the management device is configured to determinepotential effects of the individual systems from the input values andthe management device is configured to output values which influenceeffects of the individual systems.
 6. The system as recited in claim 1,wherein the management device is configured to suppress interventions byindividual systems.
 7. A method for monitoring the handling of avehicle, the handling of the vehicle being influenced by a plurality ofindividual systems, comprising: providing a management device; andmanaging the influence on the handling by the individual systems usingthe management device; wherein the individual systems include at leasttwo of an Electronic Stabilizing Program (ESP), front axle steering withsuperimposed stabilizing intervention (EAS), and chassis control withsuperimposed stabilizing intervention (EAR) and Active Body Control(ABC).
 8. The method as recited in claim 7, further comprising:communicating by the management device with control units of theindividual systems via an interface, the management device beingimplement in a control unit.
 9. The method as recited in claim 7,wherein the providing step includes providing the management device as aseparate control unit.
 10. The method as recited in claim 7, wherein theproviding step includes providing the management device in at least onecontrol unit of the individual systems.
 11. The method as recited inclaim 7, further comprising: inputting setpoint values determined by theindividual systems and actual values, into the management device;determining potential effects of the individual systems from the inputvalues; and outputting, by the management device, values which influenceeffects of individual systems.
 12. The method as recited in claim 7,further comprising: suppressing, by the management device, interventionsby individual systems.